Prncipals of Probability/Hypothesis Testing
Prncipals of Probability/Hypothesis Testing PY 211
Popular in Psychology 211
Popular in Psychlogy
This 2 page Class Notes was uploaded by Ashley Raby on Thursday February 26, 2015. The Class Notes belongs to PY 211 at University of Alabama - Tuscaloosa taught by Andre Souza in Spring2015. Since its upload, it has received 130 views. For similar materials see Psychology 211 in Psychlogy at University of Alabama - Tuscaloosa.
Reviews for Prncipals of Probability/Hypothesis Testing
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/26/15
Psychology 211 Statistics Principals of Probability A random experimentas opposed to a deterministic one is one in which the outcome is determined by chance A random experimentE the possible outcomes of E is called sample space Example a coin toss experiment 5 the possible outcomes are head or tail Then sH T Test Question Why aren t heads and tails adding up Answer Everything varies PA denote the probability of a possible outcome denoted by the letter A BA denote the probability of a possible outcome denoted by the letter B Let A and B be mutually exclusive outcomes PAorBPAPB Let A and B be independent outcomes PAand BpAxB Problem There are three doors Say you chose door number 2 Imagine there s a car behind one of the doors There s a goat behind door number 1 Should you switch doors Yes switch 1 2 3 C G G G C G G G C The rst row would cancel out The second row will count The third row will count Therefore there is a 23 chance the car will be behind door number 2 or 3 So switch Monty Hall Probability Probability Distributions a list of all outcomes and their probabilities Each probability is a number between 0 and 1 sigmaPy1 23332321017 Probability is not 1 or less A statistic a number that describes a sample Refer to sampling distribution Central Limit Theorem Mean of sampling distribution will be mean of population Sampling Distribution Mean Standard deviation of sampling distributionStandard Error same thing The bigger the sampling distribution mean the smaller the standard error Hypothesis Testing Standard Distribution distribution of sample statistics Samping Error the variability of those statistics from one sample to another Errorresidual what you expect and what you get In statistics error means random variability and not a mistake or carelessness Variance average variability The objective of science is to check whether a set of data agrees with a certain prediction 0 This prediction is called hypothesis Hypothesis is a statement about a population Hypothesis is a prediction that a parameter takes a particular numeral value or falls within a particular interval 0 Signi cance Testuses data to summarize the evidence about a hypothesis Hypothesis Testing is a systematic way to test claims or ideas about a group or population 4 Basic Steps State the hypothesis Set a criteria for decision Commute the test statistic Make a decision gtUUl 39 Usualy the null hypothesis states no effect Type 1 Error alpha Type 2 Error beta
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'